class Solution {
  public int[] sortArrayByParity(int[] A) {
    int[] ans = new int[A.length];
    int front = 0, rear = A.length - 1;

    for (int i = 0; i < A.length; i++) {
      if (A[i] % 2 == 0) {
        ans[front++] = A[i];
      } else {
        ans[rear--] = A[i];
      }
    }

    return ans;
  }
}
